We towed our '62 GlobeTrotter for a couple years with a Highlander Hybrid, and always felt perfectly safe and happy with it.
For us the beauty was the balance of having a higher mileage everyday vehicle year-round, while still being able to drop the trailer onto it and have no problems heading from Chicago to California and back.
1. A little under-powered along the steepest portions of Route 1 in northern California. So yes, I did experience Tahoe envy several times - always aware of our extra cargo.
2. Due to the Hybrid's variable-speed-transmission (in other words, no set gears) you can't effectively use cruise control while towing. It just whines and revs, not able to comprehend the additional weight. A regular V6 Highlander wouldn't have this issue, with a traditional tranny.
Long story short? It worked very well for us, a B+ experience given the fact that the rest of the time we have our big, handy SUV with 27 MPG. Now that we're up to a 22' Safari -- and planning on spending a lot more time Airstreaming -- I imagine we'll be looking for a little more oomph in our next tow vehicle soon.
Photos were taken at Costanoa campground near Santa Cruz, and a KOA on the Monterey peninsula, respectively.